The spine of most human adults consists of 24 connected bones called vertebrae. The cervical vertebrae begin at the base of the skull. Seven vertebrae make up the cervical spine, which are abbreviated C1, C2, C3, C4, C5, C6 and C7. The cervical vertebrae are smaller in size compared to other spinal vertebrae. The purpose of the cervical spine is to contain and protect the spinal cord, support the skull, and enable a wide range of head movement. The vertebrae allow the head to rotate side to side, bend forward and backward.
Frequently cervical spine disorders require surgery to relieve painful symptoms. One of the contributing factors associated with most spine disorders is the dehydration of the intervertebral disks, which act as a cushion between adjacent vertebrae. Over time these disks can dry out and become flattened, causing the vertebrae to lose height and its healthy resilience. The degeneration of the disks allow the vertebrae get closer together and cause nerve irritation, which usually stems from a ruptured disc, bone spurs or stenosis. Vertebral motion (neck movement) results in chronic pain.
Cervical fusion has become an accepted procedure to relieve the pressure on one or more nerve roots, or on the spinal cord. It involves the stabilization of two or more vertebrae by locking (fusing) them together in a desired spacing and orientation. The fusion restores the proper distance between the vertebrae thus preventing nerve irritation.
The cervical spine may be approached by the surgeon anteriorly, which refers to the front. The surgeon reaches the cervical spine through a small incision in the front of the neck. After retracting neck muscles, the surgeon often removes the affected intervertebral disk, which takes the pressure off the nerves or spinal cord. This is procedure is known as decompression. The surgeon then replaces the removed disk with a bone graft which aids in the fusion of adjacent vertebrae and restores the distance between the vertebrae. The surgeon then may use various types of plates which provide extra pressure and support the neck to make certain that the bones fuse adequately. Holes may be drilled or tapped in the bone to allow for attachment of a plate using a bone screw or other fastener.
One of the problems associated with the fusion of cervical vertebrae is the tendency of the screws or other fasteners to loosen over time. As the fasteners or screws loosen the plate is not able to support or maintain the proper orientation of the vertebrae. The plate and other associated implants, which are no longer secure, can cause irritation and even trauma to local tissue structures.
What is needed, therefore, is a system and method, which facilitates overcoming one or more of the aforementioned problems as well as other problems and to provide a device that has unique features that will facilitate reducing the risk associated with neurological surgeries and advance the present state of the art.